Home ... FAQ ... Music ... Software ... Forums ... Articles ... Contact


John Eidsvoog

John Eidsvoog


MIDI Programs and utilities
By John Eidsvoog
Released as Freeware October 2002

I am now happy to announce the freeware release of several commercial products put out by Codehead technologies. These include GenPatch,a sysex application which was actually released through Hybrid Arts. MIDI Spy, a MIDI capturing utility and MIDIMax, a MIDI mapping utility. These are released on the condition that they are not to be sold. We are very appreciative toward John Eidsvoog who has now given permission for release.

A little History

CodeHead Software was created in August of 1988 by Charles F. Johnson and John Eidsvoog, two programmers who were fed up with dealing with Atari's GDOS. They decided to rewrite GDOS in assembly language to get rid of the system slowdown that it caused and at the same time add some more new features. The program that evolved along with a desk accessory to allow loading of ASSIGN files became G+Plus, after first being called GDOS_LF (GDOS Liberation Front), ADOS, and G-Wiz. They agreed on the company name of CodeHead Software and the CodeHeads emerged.

John Eidsvoog began his programming career with the Apple II computer, another 6502-based machine for which he wrote a film composer's timing program called Film Music Tool Kit. After switching to the Atari ST, John wrote two MIDI programs for Hybrid Arts -- GenPatch ST and HybriSwitch. Many ST MIDI users know him from his famous digitized picture complete with winking eye in the GenPatch Info dialog box.

John's musical background began with a music major from Augsburg College in Minneapolis followed by a Master's degree in Jazz Composition from the New England Conservatory of Music in Boston in 1972. In the ensuing years he played piano with many bands and singers including Vaughn Monroe, Sammy Kaye, Bob Crosby, Ray and Bob Eberle, Ray McKinley and the Modernaires, Les Elgart, Tommy Dorsey Band, and the Glenn Miller Band (on baritone sax!). After moving to Los Angeles in 1976, John began doing studio sessions on piano and an array of synthesizers, playing on such TV and film scores as Dallas, Hill Street Blues, MacGyver, Knot's Landing, Simon & Simon, A-Team, Moonlighting, Twilight Zone, Popeye, Fatso, Fatal Vision and World War III. He played and composed for the John Davidson TV Talk Show and was musical director for Andy Gibb with whom he toured worldwide and made TV appearances. John also has a handful of published choir and bell choir compositions.

Gen Patch with pic of John Eidsvoog


GenPatch is a MIDI libriarian utility that lets you store system exclusive data from ANY device. It also has MIDI monitoring facilities that lets you see any MIDI data that is captured in the Atari MIDI input. Included with the program are configurations for many instruments as well as utilities to convert Dr T format to GenEdit format. Here is an explanation of the contents of the Download ( see download section):

Gen Patch Configuration screen showing TX81Z setups.

Gen Patch Midi-to Computer screen showing available devices.

There are two folders in the GenPatch Zip:

1. Genpatch1
Version dated 5/11/88. Runs only in demo mode if you don't have the sync box or the master disc.Has lots of configuration files This version was provided by myself, as I actually bought the program many years ago from B&C Computer visions. The manual is rather nice, printed on glossy high quality paper.

A "libed" version dated 3/7/87 ( an earlier version) but it is a "full" version as it is "liberated". I have full permission from the author to offer a "libed" version for download.This version also comes with a load of TX/DX7 sounds. Not as many config files as the above version however. This version is provided by Jos Vlietstra of the Atari-MIDI forum.

Please feel free to combine different parts of these versions to make up a complete version that will work on your system.If you have a Hybrid Arts Sync Box, then you will be able to run the most recent version. The demo mode however still works well.

MIDI Spy main screen


This version of MIDI Spy was provided by Trond Einar Garmo of the Atari-MIDI forum.

MIDI Spy is a MIDI recording tool that allows you to record and play back MIDI in a multi-tasking environment. It runs as either a program or an accessory. When installed as an accessory, it works completely in the background. This means that it is always in record mode (unless you disable it). As long as you haven't exhausted the memory area assigned to MIDI Spy, everything you play will be recorded regardless of your current computer activity. You can be at the desktop, within any program, or even connected to an on-line service through your terminal program.

MIDI Spy will load and save standard MIDI sequence files, allowing you to load its songs into other MIDI sequencers, or load songs into MIDI Spy that have been recorded on other sequencers and play them in the background from MIDI Spy while you work on other things, even chained together, creating a juke box effect.

*------------------- Installing MIDI Spy --------------------*

MIDI Spy runs only as a desk accessory or a stand alone program.To run it as a desk accessory simply rename the .prg extension to .acc using the show info command in the atari desktop menu. Then if you've got CodeHead's MultiDesk, you can simply use the "Load ACC" button to load MIDI Spy as a _resident_ accessory. Otherwise, copy Midi_spy.acc into the root of your boot drive and reboot your computer (making sure that you don't have more than six files with an .ACC extension).

*--------------------- Using MIDI Spy -----------------------*

Using MIDI Spy is extremely easy. Let's start by recording something. After installing MIDI Spy as an accessory, select it from the accessory (or MultiDesk) menu. The Main MIDI Spy Dialog box will appear on the screen.

If you've connected your MIDI cables correctly, you can just start playing and everything you play will be recorded (you may need to enable "Thru" to hear what you're playing if your MIDI system is set up that way). If you wait for five seconds and start playing again, a new song will be started. To listen to what you've played, just click on Play or hit the space bar. Playback will begin immediately.

MIDI Spy Help screen

Most of the buttons in the main dialog box are self-explanatory. There are also keypress equivalents for all of the buttons. Press the Help key to find out which keys may be used to control the main dialog box.

You can exit from the MIDI Spy accessory, go back to any other computer task, and start playing back what you've recorded but pressing Alternate-SpaceBar. MIDI Spy will play back your songs without affecting what you do in the foreground.

There are a number of other hot key combinations. You can find them by clicking on "Commands" in the Configuration Options box. Any of the hot key combinations can be reassigned to any combination you like by clicking on the current one and pressing another combination. You'll also notice that the same set of commands can be controlled from your MIDI keyboard. These can also be reassigned to most any MIDI command.

Once you've loaded or recorded a few songs, you'll notice the "MEMORY USED" box will display the size of the currently selected song. You can select songs by clicking and dragging within this box. Or you can start playing the current song by clicking/dragging within the current song's box. You can also right-click anywhere in the display area to switch to the "full" mode. The entire box will become gray and a vertical line will show the current spot in the song while playback is in effect. You can also select a mid-start point and begin playback by clicking within this box.

TIPS by Trond Einar Garmo of the Atari-MIDI forum

If you go to configurations and check the "MidiMax mode" you will be able to capture the MIDI out from some programs, but not all. About half of the programs that I tried worked. I tried several of the algorithmic programs on TAMW. MIDI Mouse and Ludwig did not work.

One other tip: for those programs that won't capture the output, it might be possible to loop back the MIDI output to the in-port (by way of the MIDI through on the synth) and record it from there. If you turn off MIDI thru on MIDI spy and the main program I think this should work - I have tried it once. So if MIDI Spy and the other program will co-exist happily, this might be the solution.

I think MIDI Spy was intended to be a program that was always ready to record in the background of any program, like if you got a moment of inspiration when you were working with your word processor. And it could also be a juke-box for MIDI in the background when you were doing other things.

Trond Einar


MIDI Max main screen


MIDI Max is a MIDI mapping utility that allows (for example) chords to be assigned to MIDI keys, Midi Macros to be triggered and a host of other features. This version was provided by Alexander Maas. Perhaps more documentation will come, but for now, use the click and learn method. There is some documentation in the Zip. While this program was actually programmed by another codehead member ( Larry Herzberg), John has given permission for the download as long as the program is not sold.


Download GenPatch

Thanks to Greg Malecha, the manual is now available as scanned graphic files: 4MBS each

Download GenPatchST_Manual1

Download GenPatchST_Manual2

Download MIDI Spy

Download MIDI Max

Codehead page at Sky Blue Music

Another Codehead page

John Eidsvoog's Sky Blue Music: Check it out!